One way to keep levels of scouting budgets higher could be to have a end of year/rollover scouting report on the strength of the upcoming season's Draft/IFA/Free Agency Pool that is determined by your scouting budget. Then players could use that information to set budgets which could be a big advantage.  For example if you have 20 in IFA scouting you would have a good idea that a strong crop is coming and to bump up your prospect budget or also drop it down if it looks like this years crop isn't as good.  This would be also be consistent with real life as scouting is a continual, multi-year process.  You could also add updated reports during the year after you have set the budget.  Would be even better if it had descriptions like top-heavy or deep but any indications would add additional incentives to maintain higher scouting budgets. 

The problem I see with this is how subjective player value is. A lot of the time, I'd prefer a player with an overall in the low 70s over a guy with an overall in the high 80s depending on their defense, splits, etc.

While everyone certainly values players a bit differently and OVR is not the greatest indicator of true value, I think it would still be a pretty great "extra" to work in. Just knowing a ballpark of depth of an upcoming draft would be pretty helpful.

Makes sense for IFA but not HS/College.   6m is the minimum and, regardless of how deep a draft is, you know exactly what slot money is.   Unless the new program starts dropping quality into the 3rd-7th round, you still know how much your draft will cost you.